如何使用 jest 模拟 @google-cloud/kms

Question

我正在尝试编写解密的单位测试用例。我自己的实现了解密加密文件的实现。试图导入面对以下错误的decrypt.mjs。

必须使用导入加载ES模块：/Node_modules/bignumber.js/bignumber.mjs

我的应用程序是React Frontend和Nodejs后端。我已经为nodejs使用了ES6模块。这是

import { readFile } from 'fs/promises';
import path from 'path';

import { KeyManagementServiceClient } from '@google-cloud/kms';

const decrypt = async (APP_MODE, __dirname) => {
  if (APP_MODE === 'LOCALHOST') {
    const keys = await readFile(
      new URL(`./stagingfile.json`, import.meta.url)
    ).then((data) => JSON.parse(data));
    return keys;
  }
  const { projectId, locationId, keyRingId, cryptoKeyId, fileName } =
    getKMSDefaults(APP_MODE);
  const ciphertext = await readFile(
    path.join(__dirname, `/${fileName}`)
  );
  const formattedName = client.cryptoKeyPath(
    projectId,
    locationId,
    keyRingId,
    cryptoKeyId
  );
  const request = {
    name: formattedName,
    ciphertext,
  };
  const client = new KeyManagementServiceClient();
  const [result] = await client.decrypt(request);
  return JSON.parse(result.plaintext.toString('utf8'));
};

const getKMSDefaults = (APP_MODE) => {
//Based on APP_MODE the following object contains different values
  return {
    projectId: PROJECT_ID,
    locationId: LOCATION_ID,
    keyRingId: KEY_RING_ID,
    cryptoKeyId: CRYPTO_KEY_ID,
    fileName: FILE_NAME,
  };
};

export default decrypt;

我尝试使用手动模拟（JEST）模拟@google-cloud/kms的Decrypt.mjs文件，但它不起作用。我尝试了多个解决方案来模拟，但没有任何效果，但它以导入来加载ES模块错误而结束。

Answer 1

我已成功使用 jest 通过 TypeScript 模拟 @google-cloud/kms，因此希望这与您可以使用的 ES 模块的过程相同。

示例工作代码：

// jest will "hoist" jest.mock to top of the file on its own anyway
jest.mock("@google-cloud/kms", () => {
  return {
    KeyManagementServiceClient: jest.fn().mockImplementation(() => {
      return {
        encrypt: kmsEncryptMock,
        decrypt: kmsDecryptMock,
        cryptoKeyPath: () => kmsKeyPath,
      };
    }),
  };
});

// give names to mocked functions for easier access in tests
const kmsEncryptMock = jest.fn();
const kmsDecryptMock = jest.fn();

const kmsKeyPath = `project/location/keyring/keyname`;

// import of SUT must be after the variables used in jest.mock() are defined, not before.
import { encrypt } from "../../src/crypto/google-kms";

describe("Google KMS encryption service wrapper", () => {
  const plaintext = "some text to encrypt";
  const plaintextCrc32 = 1897295827;

  it("sends the correct request to kms service and raise error on empty response", async () => {
    // encrypt function is async that throws a "new Error(...)"
    await expect(encrypt(plaintext)).rejects.toMatchObject({
      message: "Encrypt: no response from KMS",
    });
    expect(kmsEncryptMock).toHaveBeenNthCalledWith(1, {
      name: kmsKeyPath,
      plaintext: Buffer.from(plaintext),
      plaintextCrc32c: { value: plaintextCrc32 },
    });
  });

});